Circuit breaker



Feb. 19, 1935. w, M, EEDS 1,991,991

CIRCUIT BREAKER Filed latch 18, 1932 2 Sheets-Sheet 1 Z 7 lz'gr 4 I 1 W/TA/E5355, INVENTCR 1 h .4 d 4 Mn) Pop/W ee 5 9a! BY I ATTORN Y Feb. 19, 1935. w. M. LEEDS CIRCUIT BREAKER Filed March 18, 1952 2 Sheets-Sheet 2 'ATTbRN Patented Feb. 19, 1935 UNITED STATES CIRCUIT BREAKER 'Winthrop M.-Leeds, Wilkinsburg, Pa, assignor to Westinghouse Electric & Manufacturing Com- PW, a corporation of- Pennsylvania Application March 18, 1932, Serial No. 599,678

' 18 Claims. 1 (01.200-150) My invention relates to circuit interrupters and; more particularly, to circuit breakers in which are extinguishers of the side-vented chamber type are provided for extinguishing the arc.

5 This application is a continuation in part of patent application 510,990 oi. B. P. Baker and W. M. Leeds, filed January 24, 1931, and assigned to the assignee of this application.

This type of arc extinguishing structure usually comprises a stack 0! plates of insulating ma-' terial between which are placed a plurality of plates of magnetic material at spaced intervals. Aligned slots are provided in both' the insulating plates and the iron plates forming an elongated groove within which the arc is drawn. The are is moved laterally in the groove, due to the dis-- tortion of the magnetic field around the are by the magnetic plates, in contact with the edges of the insulating plates which retain oil adjacent the arc path. This oil is decomposed giving off a large volume of gas whichpasses turbulently through the arc stream to deionize the arc and prevent its reignition after the first zero point on the alternating current wave.

One object of my invention is to provide means for securing equally satisfactory operation of an arc extinguishing structure of this type, on both heavy and moderate currents.

Another object of my invention is to generally improve-the operation of existing arc extinguishing structures. or the general type herein described. 1

A further object of my invention is to provide novel means .ior venting arc extinguishing strucof said structure.

In previous structures of this type it has been observed that it is easier to extinguish the arcs caused by heavy currents than those caused by moderate currents. This apparent phenomenon may be explained when the actionoi the arc extinguisher structure'is examined.

when a high current is being interrupted, the arc. energy is high. This results in a large quantity or oil being decomposed to supply a large volume of gas to extinguish the arc. The amount or gas available for deionizing the arcis further increased with high current arcs since the 'resultant electro-magnetic forces exerted by the slotted magnetic plates, tending to move the are further into the deionizingstructure, are very large. As a result, the arc is quickly forced into the slots where it is moved into contact with.

freshv volumes of oil giving a continuous supply tures, which means shall improve the operation these heavy current arcs are extinguished in the upper portion of the arc'extinguishing structure .before the arc is drawn the full length of the stack of plates. With moderate current arcs,

however, an insufilcient quantity of gas is genarrangement which I employ in the construction and venting of the arc extinguishing structure. Specifically, I vent the arc extinguishing structure in the upper part of its length, where restricted vents cause a confinement of the gases produced by the are within the structure, and by having the groove without vents at the lower portion of the stack of plates, the gases formed within the lower portion of the structure are caused to fiow upwardly and longitudinally vthe arc' is first drawn, and restrict or entirely omitvents in the lower part. In operation these through the arc, thus making more effective use of smaller amounts of gasgenerated to deionize the arc. n

These and other. objects and advantages of my invention will be made further apparent from the following description or the accompanying drawings, in which: Figure 1 is a sectional view through a circuit breaker embodying my invention, showing the interior parts in elevation; 1 Fig. '2 is a sectional viewof the stack of deionizing plates, taken on the line IIII of Fig. 3;

Fig. 3 is a sectional view through the stack of deionizing plates taken on the line III-III '0! Fit Fig. 4 is an enlarged sectional view of ,one 01" the vented groups shown in Fig. 2, the thickness or" the plates has been exaggerated for clearness;

Figs.5,6,'l,8,9and10areplanviewsshowing k the individual plates which comprise the arc'ex tingu'ishing structur Referring. to Fig. 1, the circuit breaker 10 comprises a liquid-tight tank or container 11, which is filled with oil or, other insulating liquid 13. Current conductors 15 extend through in sulating-bushings 17 which are secured by flanged The lower end of each of the conductors 15 isprovided with a stationary contact Structure 21.

Electrical connection is made between the con-- tacts 21 by means of a conducting bar 23 having upstandingtips 25. The conducting bar 23 is actuated to open or close the circuit "breaker through an operating rod 22 by a suitable mechanism (not shown).

A stack of deionising plates 27, held together by retaining means such as bolts 16, is secured to the ends of the conductors 15. The are extinguishing structure is formed by assembling ,a plurality of groups of the plates shown in Figs. 5, 6, '1, 8, 9, and 10, each of said groups of plates comprising a pair of fibre plates 29 having therebetween a slotted plate 31, of magnetic material and a lining member 33 of fibre, and spacing plates 35 or 36 of fuller-board or other insulating material. The plates 35 are used to securethe vented groups, and the plates 36 are used for the unvented groups. .The top insulating plate 30 includes a slot 3'! to permit the e of the contact tip when making contact with the 25 main contact 43, and an arcing contact 32 connected by a shunt 34 tothe conductor 15. On the'bottom of the s ck. a second similarly slotted insulating plate 38 is aflixed.

The fibre plates 29 have a slot 39 extending from the wider slot 3'7 which is common to all the plates of the structure. The plates and 36 have 40 arranged in the extension of slot 3'! for the purpose of retaining 011 along the arc path where it will be decom- 35 posed to supply gas for deionizing the arc. The plates 35 which space the groups of iron and fibre plates at the top of the stack havean additional slot 41 extending to the outer edge thereof which vents the groove formed by slots 37 -40 on bly. The eflect of the slot 42in the magnetic plate 31 is to cause the magnetic field set up by the arc to force the are into slot 39. The fibre lining 33, which is placed within the slot 42 of the plates 31, protects the edges of the slot in each of the plates 31 from the arc.

The main contact member 43 is biased down- -wardlybyspring44soastoclosetheopening3'l in the t plate 30 after the withdrawal of the contact tips 25 thereby effectively sealing the top ofstructure 27, Also, since the slot 371 is the only opening in the bottom plate 38 and since it is closed by the moving contact 25, substantiallyallofthegasesformedbythe arcmustbe vented through the slots 41 in the plates 35 in 56 the top half of the stack. Thus, the gases formed in the groove resulting from the assembly of the plates, all of which have the similar slot 37, are forced to flow longitudinally through the are, especially when the arc is drawn into the lower 60 portion of the groove. Theincreased gas gencation and the large magnetic forces accom ,panyingaheavy currentarcresultinthe com plete and rapid t of that are in the toppartofthestructureadiacenttothevents.

0 6'Ihelines43and44illustratethepathstaken by high and medium current arcs, respectively, I

-.veryshortlyafterthearcsareestablished. The "forceofthemagneticfieldtransi'ersthearcal- 'mosttelytothearcingcontact'orhom ,7032,anditapparentthateventherela- I 1,091,901 collars 19 to the top of the tank or container 11.

While a liquid circuit breaker has been shown in the drawings, I do not wish to limit my invention to that type of circuit interrupter, because the broad idea is applicable to other types as Well;

Also; while the foregoing specification has described how my invention might be applied to one specific type of arc extinguishing structure,

I I do not wish to limit myself to that type of structure except in the manner specified in the following claims. v I claim as my invention:

, 1. In an arc extinguishing structure for a circuit interrupter, a groove, means for causing an arc in said groove, said groove being closed on the end where said arc is drawn, plates of magnetic material adjacent to said groove for moving said are in said groove, and means for vent- .ing said structure only in the neighborhood of said closed end.

2. In an arc extinguishing structure for a circuit interrupter, a body of liquid, a groove, a fixed contact and a movable contact for drawing an arc in said groove, plates of magnetic material adiacent to said groove for moving said are in said groove, and means for venting said structure on the side at the end adjacent said fixed contact only.

3. In a circuit interrupter, an arc extinguishing structure, said structure including a plurahty of groups of plates, each group including an insulating plate and a plate of magnetic material, said plates having aligned slots forming a groove in which said are is drawn, means for closing one end of said groove, and means for venting said structure on the side only in the neighborhood of said closed end.

4. In a circuit interrupter, a of liquid,

means for establishing an are, an arc extinguishing structure, said structure including a plurality of groups of plates, each group including an insulating plate and a plate of magnetic material, said plates having aligned slots formend of said groove where the arc is initially es tablished.

5.- In an arc extinguishing structure for a circuit interrupter, a plurality of slotted plates arranged in groups of two or more insulating plats and one iron plate, said slots aligning to form a groove within which said arc is drawn, the transverse length of said groove being several times its transverse width, and'means for venting saidgroo've along one side onlyintha'tportion where the arc is initially drawn.

6'. ma circuit interrupter, an extinguish-' ing structure, said structure including a plurality of ,groups of. plates, each group including a pair of plates of insulating material having.

slots therein, a plate of magneticmaterial having a slot therein interposed between -said insulating plates, and a plurality of plates of insulating material having slots therein and recesses'along saidslotasaidslotsinallcfsald,

platesbeingalignedto'formagrooveinwhich saidarcisdrawmsaidgroovebeingventedalong one side thereof in that portion where the arc isintiallydrawnandbeingunventedalmg remainingportionofsaidside. I

'Llnacircuitintu'ruptenabodyonflimid.

'anarcextinguishing structureJaidstructm'eim eluding apluralityof groups of plates, each groupincludingapaifofplatesolinsulaflngmateri al having slots therein, a plate oi magnetic material havinga slot therein interposed between said insulating plates, and a plurality of plates said are in said pe, said w e beingsubstantially closed on* the end where said arc is initially established, and means for venting said oi absorbent material having slots therein, said passage only in the neighborhood of said closed slots all being aligned to form a groove in which saidarc is drawn, and means for venting said structure along one side, only in that portion where the arc is initially drawn.

8. In a circuit interrupter, an arc extinguishing structure, said structure including a--plurality of groupsof plates, each group including a pair of plates of insulating material having slots therein, a plate of magnetic material having a slot therein interposed between said insulating plates, an insulating strip between'saidinsulatfor venting said structure along one side, only in that portion where the arc is initially drawn.

9. In a circuit interrupter, abody'of liquid, an arc extinguishing structure, said structure inend. k 13. In a circuit interrupter, means defining a passage, means for establishing an are within said passage, means including members of magnetic material for moving said are in said passage, said passage being substantially closed on the. end where said are is initially established, and means for venting the side of said e only adjacent said closed end. 7

14. In a circuit interrupter, means of insulating material defining the walls oi a chamber having a centrally disposed passage extending therethrough, means'ror establishing an arc within said e, means for closing said e at the end wheresaid are is initially established, means of magnetic material imbedded in the walls surrounding said for moving said arcin said e, and means tor venting one side of said e only in the neighborhood of said closed end.

eluding a plurality of groups of plates,'each 15. In a circuit.interrupter, a I her having group including a pair of plates of -insulating material having slots therein, a plate of magnetic material having a slot therein interposed between said plates, an insulating strip between said insulating plates'for protecting the edge 02- said magnetic plate from the arc, and a plurality of plates of fibrous insulating material having slots therein, said slots all being aligned, 1'40 term a groove in which said are is drawn,

- means for some of said groups and other of said groups being imvented, and all of said vented groups being bled in that portion lafed therein interposed between said plates, rf id strip between saidinsulatingplates i'or protecting the edge of said magnetic plates from the are, a plurality of plates at absorbent material havingsslotsthereinandreecssesalong saidslotasaidslots'allbeingalignedtoionna grooveinwhichsaidarcisdrawmmeansiorclosingoneendoisaidgroovameansforventingwalls of insulating material and centrally disposede extending'therethrough, a sta tionary contact means 'positioned'at one end of said e and a contact member movable through said passage to establish an arc therein, said stationary contact means'being adapted to substantially close one end of said e, said movable contact member being adapted to close the other end of said e while-establishing said are therein, means of magnetic material imbedded in the walls oisaid chamber and insui'rom' said e ior movingthe arc in and means for venting one side 01 M r only adjacent said stationary con- 16. In aycircuit interrupter, means at least partly of insulating material-tor defining apassage, means lorestablishing an are within said n w magnetic means for moving the are in e, and means, adjacent one ,torventin'gsaid H means for causing a considerable portion of the are products to w substantially longitudm u oi. m

17. In a circuit interrupter, means at least partly of insulating material for defining a passage, means for. establishing an arc withimsaid,

e, means of magnetic material for moving said somemi saidgroups to one sidethereof, other oi the In in 1 and means 1 v tin said'groups being imvented, said vented groups beingallassembledinthatportionotthestructureadJacent'-tosaidflxedcontact.

11. In 'a circuit interrupter, means at least partlyotinsulatingmaterialiordeflningapas-V- sage, means for establishingan are within said meansior moving said are in said e, e'being substantially closed on the end where said are is initially established, and means-tor venting said e only-in the neighborhood of said closedend.

12. In a-circuit interrupter, meansior defining a e that is lined with insulating material,

means for establishing within said passage, means of magnetic material i'orrmoving' said ,andmeansi'or causing considerable portionot the are products to flow substantially longitudinally of said .1 1 etoward said vent-v 18. In a circuit interrupter, means at least partly of insulatingmaterialiordeflninga'passo,

defining the passage causing a major portion or .v

the are products to flow in said -e toward said end where the arc isinitially established. 

